The Classic Machinery Network

Hi all
I have just bought a Thwaites orion dumper.
previous owner advised brakes not working.
after raising it one wheel is not rotating.
after removing split pin and castle nut the hub is very stiff to shift , so assume the brake linings are stuck solid to the hub.
other wheel spins freely
Any clues as how to take the hub off ?
a previous owner must have tried or succeeded at one point as part of the rim of the hub has been cracked off.
the Adjusting bolt on the inside of the stub axle is also pretty rusty
not sure how to approach this
will try and post a few pics when my phone is charged
Thanks for any help
Andrew

see pics

Hi Andrew, you have a common drum brake problem there, my only advice would be to try and free off the brake adjuster first then back it off, the damaged brake drum is an issue and should be replaced. I have never worked on one of these so can I ask is the drum and hub one complete unit, because normally they will be separate pieces?
Look on the front of the brake drum and see if there are two opposed tapped holes? If so these would be to screw bolts in to pull the drum from the hub, so long as the threads are good them you should be able to use them to pull the drum.
Failing that try a puller, let us know how you progress.

Jeremy

yes looks like the drum is seperate and should pull off.
Thwaites were good enough to send me a piccy
No bolt threads unfortunately
I will try and back the adjuster nut off, but its pretty rusty ,the thread and nut , try heat I suppose
my worry is that the brake shoes will not fall back to a nuetral position and will get caught up on the inside of the drum and make removal impossible, especially if its worn a groove on the inside of the drum?
what a pain

piccy

It should still come off, it may need some brute force but it will come off, as it is already damaged I would be looking at getting a new drum anyway they don't last forever plus what you replace one side, then you should also replace the other side as a matter of course. Worst case scenario is to break it but that should be your very last resort.

Jeremy

If you can free of the slack adjuster with heat and releasing fluid then you can tap the brake drum and hopefully the springs should pull the wedge adjusters back in, as Jeremy said even if there is a lip on the inside of the brake drum they should still come off and bring the brake shoe with it, it may damage the brake shoe but as is it’s unusable so there’s always casualties in war as I say! Good Luck
Ian

update
had to get my Mapp torch back
have tried backing off the nut by applying several cycles of heat and ac-50, but no joy
have walloped the hub with a copper hammer it now moves freely which is some progress
have looked at this and will see if I can borrow an air hammer
very interesting method
will let you know

https://www.youtube.com/watch?v=StGnq7vMV5A&t=27s

This is the same question as a couple of days ago . Have a look at previous thread and answers in dumpers . Seems like a pretty common problem with these small thwaites dumpers . I don't think the hubs are that easy to get hold of ( unless someone knows otherwise ) so take care !

Further update
success!
I used a heavy duty hammer drill on hammer only function and cut off a used chisel so it was flat, as per youtube video sprayed water into the wheel stud bolt holes and literally within a few minutes the hub was loose. I just moved the chisel around each stud. gobsmaked it was so easy
I have tried removing the metal with the studs with a hub remover , it has budged a bit but will not come off. I have removed the brake shoes
and the inside of the hub and shoes were completely covered in thick greasy gunge
have cleaned it all off , one shoe seems to have worn more than the other, they have been riveted . please see pics
is it worth having them relined?

At the hub mechanism that the brake rod attaches to it was not moving that freely , with some gt85 and some giggling its loosened up,but if you look at the brass grooved part that the brake drum/lining rests on one comes out far more that the other when the rod is pulled, should they both come out a similar amount? perhaps that explains the difference in brake wear?

Inside of the hub is now nice and clean with no wear grooves

to further clean linings is it safe to ultrasonically clean?
Thanks all
progress being made!
Andrew